Light emitting device and display unit which make use of porphyrin derivative compound

Abstract

A light emitting device is disclosed having a light emitting layer containing a porphyrin derivative compound each pyrrole group of which is characterized by having a straight-chain or branched side-chain alkyl group having 5 to 20 carbon atoms, and the central metal of which is Cr, Ni, Cu, Co, Ru, Rh, Pd, Ir, Pt or Au. The compound is light-emissive and especially has phosphorescent light emission properties and liquid crystal properties. Also disclosed is a display unit using the light emitting device.

What is claimed is:  
     
       1. A light emitting device comprising a pair of electrodes and, between the pair of electrodes, a light emitting layer comprising a porphyrin derivative compound represented by Formula (1) or (2)                    
       wherein R or R′ represents a straight-chain or branched alkyl group which may be substituted with a halogen, provided that the number of carbon atoms contained in the alkyl group is 5 to 20 and one methylene group, or two or more methylene groups not adjacent to each other, in the alkyl group may be replaced with —O—, —S—, —CO—, —CO—O—, —O—CO—, —CH═CH— or —C≡C—; and M is Cr, Ni, Cu, Co, Ru, Rh, Pd, Ir, Pt or Au, which M may be combined with a halogen, an oxygen, —OH or ═CO, and 
       wherein the porphyrin compound is a liquid crystalline compound and is capable of emitting light upon application of a voltage to the pair of electrodes.  
     
     
       2. The light emitting device according to  claim 1 , wherein in said compound represented by Formula (1) the M is Pd, Cu, Pt or Au and the M may be combined with a halogen, an oxygen, —OH or ═CO. 
     
     
       3. The light emitting device according to  claim 1 , wherein the light emission is phosphorescence. 
     
     
       4. The light emitting device according to  claim 1 , wherein said compound represented by Formula (1) or (2) is capable of charge injection upon application of the voltage to said pair of electrodes. 
     
     
       5. The light emitting device according to  claim 1 , wherein said compound represented by Formula (1) or (2) has a liquid crystal state in accordance with temperature. 
     
     
       6. The light emitting device according to  claim 5 , wherein said liquid crystal state is a discotic liquid crystal state. 
     
     
       7. The light emitting device according to  claim 1 , wherein said compound is represented by Formula (1) where M is Pt. 
     
     
       8. The light emitting device according to  claim 1 , wherein said compound is represented by Formula (1) where M is Cu. 
     
     
       9. The light emitting device according to  claim 1 , wherein said compound is represented by Formula (1) where M is Pd. 
     
     
       10. An image display unit comprising the light emitting device according to  claim 1 , and a drive unit which enables the light emitting device to form a desired image.